High speed typewriters



Dec. 18, 1962 Filed Feb. 20, 1961 Fig./

R. H. ARTHUR HIGH SPEED TYPEWRITERS 2 Sheets-Sheet 1 INVENTOR I RONALD H. ARTH 4% $7 524 Dec. 18, 1962 R. H. ARTHUR 3,0 8, 8

HIGH SPEED TYPEWRITERS Filed Feb. 20, 1961 2 Sheets-Sheet 2 Fig.2

k) r z N z [N 66 a; 66 66 i 66 KEY sa as 0288mm :2.

if I06 N l I 1 PE om:

DETECTOR AMP Sag/T INVENTOR RONALD H. ARTHUR 92 93 94 BY M M This invention relates to high speed typewriters or like business machines; more particularly it relates to a high speed typewriter characterized "by duplicate type bar sets; and specifically it relates to a high speed typewriter having duplicate type bar sets which are alternately controlled.

' At present typewriting machines are provided with a single set of type bars adapted to move from a position of rest to a common printing point. This arrangement of necessity requires that the time interval between serially powered type bars be such that a type bar receding from the printing point will not encounter a type bar approaching the printing point. This interval must be at least equivalent to the time required for the center type bar to recede from the path common to the type bars adjacent thereto. As is apparent from the above the speed at which a typewriter may be operated is limited by the neoessity to delay the actuation of successive type by said interval. Further in present single basket typewriters, repeat actuation of a type bar requires that the bar return substantially to rest position before being actuated a second time.

In accordance with the present invention there is provided a typewriter having two sets of type bars. The fulcrums of the type bars in each set lie in planes perpendicular to the axis of the platen and on opposite sides of a common printing point. The two sets of type bars are adapted'to be alternately controlled from a single keyboard whereby type faces on the sides of flexible bar ends are moved in front of a common printing point in position for actuation by a hammer.

As will hereinafter be more clearly evident, with this novel construction and arrangement, the time interval required between serially operated bars is materially reduced thereby permitting typewriter operation at much higher speeds and also permitting repeat characters to be operated at normal operating speed.

A further feature of the invention resides in the fact that the type faces are disposed on the sides of the bars, whereby the type heads may be thinner thereby permitting a greater number of type bars per unit arc to be positioned on the head rests.

An object of the invention is to provide a high speed typewriter.

Another object of the invention is in the provision of a typewriter having two sets of type bars.

Another object of the invention is in the provision of a typewriter having alternately controlled duplicate sets of type bars.

A further object of the invention is in the provision of a typewriter having two sets of type bars disposed on opposite sides of a common printing station.

' A still further object of the invention is in the provision of flexible type bars adapted when positioned to be moved by a hammer to effect printing.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a partial perspective view showing the ar- United States Patent 0 3,068,985 Patented Dec. 18, 1962 "ice rangement of two duplicate sets of type bars relative to a common printing station;

FIGURE 2 is an elevational view similar to FIGURE 1 showing a type bar actuated to printing position;

FIGURE 3 is a block diagram of circuitry for operating the two sets of type bars alternately;

FIGURE 4 is a side elevational view showing the type bar hammer and photoelectric apparatus in accordance with the invention; and

FIGURE 5 is a timing diagram explanatory of the typewriter operation.

Referring now to the drawings there is shown in FIG- URES l and 2 a horizontally disposed platen 12 rotatably mounted on a carriage 13 whose movement relative to a frame in letter space direction is under the control of a conventional two dog partial drop escapement mechanism such as is used in Royal Typewriters. Suitably mounted for movement in a vertical direction relative to the typewriter frame in order to effect case shifting in a conventional manner is an arcuate 90 double type bar segment 14. The type bar segment is located centrally of the frame and forwardly of the platen and lies in a plane perpendicular to the axis of the platen. As shown in FIGURE 1 type bar guides 16 and 18 are mounted on op-. posite sides of the central portion of the segment. Ribbon guides (not shown) are mounted on the forward legs of the two type guides whereby a ribbon 15 (FIGURE 4)' in front of the printing position may be indexed as is understood in the art. Two identical sets of actions are adapted to be rotatably mounted on fulcrum wires 20 and 22 respectively secured in opposite sides of the segment periphery thereby to rotatably mount in each slot 24 milled in the segment, type bar drive arms 26 and type bars 28. Each drive arm 26 is formed with an ear 30 and a bent over tab 32 on one side of its fulcrum and a tail 34 on the other side of its fulcrum. Each ear 30 carries a stud 36 which anchors one end of a motion transmitting spring 38 whose other end is anchored to a stud 40 on its associated type bar. As shown in FIGURES l and 2 the bent off tab 32 overlies the upper edge of its associated type bar and has secured thereto a shock absorbing pad 42. for reasons which will hereinafter be apparent. The tail of each drive arm is connected by a link 44 to an associated bell crank 46. All of the bell cranks associated with type bars mounted on one side of the double segment are fulcrumed on a shaft 48 extending from front to back of the machine and suitably secured to the machine frame, and those on the other side are similarly mounted on a shaft 50. Each bell crank 46 is connected to an arm 52 which is mounted on and adapted tobe driven by a cam 54 formed on one face of an associated clutch plate 56. The other faces of. the clutch plates 56 are in frictional engagement with clutch discs 58 keyed to and driven by shafts 60 which in. turn are continuously driven from a suitable motive source (not shown). As shown in FIGURES l and 2 shafts 60 extend freely through the clutch plates and eccentrically of the cams. Each clutch plate 56 is formed with a peripheral step 62' ciated and its clutch disc 58 frictionally drives the clutch plate through one revolution. The cam 54 on the revolving clutch plate drives the arm 52 associated therewith thereby driving the action associated therewith through a cycle. The developed periphery and eccentricity of the cams are such as to impart controlled acceleration to the type actions over a full cycle.

As is apparent from FIGURES 1 and 2 as a type bar drive arm 26 is accelerated by its associated bell crank it carries the type bar 28 connected thereto by an associated motion transmitting spring 38. Hence both move toward the type guide. As shown in FIGURE 2 a yield member 68 is secured to the top edge of the segment between the type guides 16 and 18 in the path of the edge 69 of the type bar actuated. After the type 'bar encounters the yield member 68 the type bar drive arm 26 will continue to move through its initial half cycle, the segment being provided with a cutout 70 (FIGURE 1) to permit this, thereby causing the motion transmitting spring 38 to stretch. While the drive arm is being so overdriven as to stretch the spring, and during the interval that the drive arm is moving back and the spring is returning to normal, the actuated type bar 28' remains stationary in the type guide 18. During the time the type bar 28' remains stationary a print hammer controlled by a solenoid strikes the type head to effect printing. As the drive arm 26 is returning the resilient member 42 absorbs the shock when the drive arm encounters the type bar 28.

As shown in FIGURES 1 and 2 type characters 72 are secured at the type bar extremities on the side of the bars facing the platen thereby to effect printing through the inked ribbon when the bar extremity is struck and flexed toward the platen by a hammer blow effected by the armature 76 of a hammer solenoid 78 (FIGURE 4).

As shown in FIGURE 3, to which reference may be made, each set of actions disposed on either side of the double segment is controlled by solenoids 66 in an associated set of solenoids generally designated 80 and 82. One side of all the solenoids 66 in set 80 are connected to one side of a flip-flop circuit 84. Similarly one side of all the solenoids in set 82 are connected to the other side of flip-flop 84. The solenoids 66 in each set which correspond to a particular character are connected to a discrete one of output lines 86 representing the characters. The output lines are adapted to be selectively energized upon closure of switches in response to the depression of the keys on a keyboard or from the output of a decoder as will be understood by those skilled in the art. The state of the flip-flop 84 determines which set of solenoids 80 or 82 is conditioned for operation by grounding one or the other sets of solenoids, depending on which side is on, whereby a selected solenoid 66 in the conditioned set 88 or 82 will be energized when a signal is generated on its associated line 86. The state of the flip-flop 84 is changed during each typing stroke in response to a feedback signal thereby to condition or ground the other set of solenoids whereby the sets are alternately conditioned.

The apparatus for generating a signal for changing the state of the flip-flop circuit 84, energizing the hammer solenoid 78 whereby hammer 76 is operated, and energizing an escapement dog actuating solenoid 88, whereby escapement dogs 89 and 90 are rocked to and fro in response to energization and de-energization of the solenoid 88, respectively, is shown in FIGURES 3 and 4. This apparatus comprises respectively a light source 91 and a photocell 92 suitably mounted on the upper edge of the double segment between type guides 16 and 18 and to either side of the path of the type bar. The light source 91 is positioned to direct light toward the photocell. In operation when the forward edge 69' of a type bar extremity from either basket moves into the field of vision of the photocell, and while the type bar is in the guide, the light received by the photocell decreases and a signal is generated by the photocell. As shown in FIG- URES 3 and 4 the signal generated is connected to an amplifier 93 and thereafter to a one-shot multivibrator 94. The multivibrator 94 generates a pulse of predetermined duration which is employed to switch the state of the flip-flop circuit 84, and simultaneously to energize the hammer solenoid 78, and the escapement dog actuating solenoid 88.

The operation of the instant apparatus may be understood more clearly by reference to the timing diagrams of FIGURE 5. Time t represents the time at which a signal pulse 95 is generated on a discrete one of output lines 86, either by key depression or as a result of a tape sensing and decoding operation. This signal energizes a discrete type action control solenoid 66 in the set of solenoids, e.g. set 80, conditioned for operation by flipflop 84 which assumes one of its stable states when power is turned on. At time t the current (curve 96) in the energized solenoid 66 is eifective to pull its armature 64 thereby initiating a type action whose controlled motion is illustrated by curve 97; the interval between points a and b in curve 97 representing the time the type bar is stationary in the type guide. Time t represents the time at which the light is interrupted by the type bar actuated thereby generating a signal which after amplification as heretofore explained operates the one shot multivibrator 94 to generate pulses 98 of predetermined duration. The generated pulses 98 are employed over conductor 180 (FIGURE 3) to switch the state of flip-flop circuit 84 thereby to condition set 82 whereby the subsequent energization of a line 86 will energize a solenoid in set 82 to initiate an action fulcrumed on the opposite side of the segment. The generated pulse also energizes solenoids 78 and 88 whose current curves are designated 102 and 183 in FIGURE 5. At time 1 the hammer solenoid current is sufiiciently built up such that the hammer, whose motion is illustrated by curve 104, strikes a positioned type bar at time t Also at time 1 the escapement solenoid current 103 is suificiently built up such that its armature rocks the escapement dogs 89 and 90 forwardly thereby freeing the carriage 13 for movement. However, in that the mass of the carriage is relatively great, its movement (curve 105) is delayed until after the hammer strikes the type bar; its initial escapement occurring between times 1 and t As shown in FIG- URE 5, at time 1 the one shot multivibrator 94 switches back to its quiescent state thereby causing the hammer and escapement solenoids to be de-energized. At time 1 after the carriage has partially escaped, the escapement solenoid current, whose decay time is delayed by a diode 106' in parallel therewith, permits the armature thereof to rock the escapement dogs back to normal to permit movement of the carriage through the remainder of its escapement between times t; and t As shown in FIGURE 5 another signal on a line 86 may be generated at time t after the flip-flop circuit 84 has switched state at time t such that another action can be initiated at time t while the first action is half way through its cycle.

It should be understood that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention claimed is:

1. In a typewriter comprising a frame and a carriage supported for movement on said frame relative to a printing station, a type bar segment mounted centrally of said frame and orthogonally with respect to the direction of carriage movement, two identical sets of type bars mounted respectively on opposite sides of said segment, means for selectively driving said type bars in each set to said printing station, means for conditioning one of said type bar sets for operation, means responsive to the movement of a type bar toward said printing station for conditioning the other set of type bars for operation, and means responsive to said last named means for operat ing a hammer to effect printing by the type bar positioned at the printing station.

2. In a type writer comprising a frame and a carriage mounted for movement relative to said frame, a segment mounted orthogonally with respect to the direction of carriage movement, two sets of type bars mounted respectively on opposite sides of said segment, said type bars upon actuation being adapted for movement to a printing station in front of and parallel to the printing plane defined by said carriage, type characters mounted on the sides of said type bars facing said printing plane when said type bars are positioned at said printing station, means operative to alternately condition said sets of type bars for operation, means for selectively actuating a type bar in the conditioned set of type bars, a hammer adapted to strike a type bar positioned at the printing station, and means responsive to the movement of a selected type bar from the conditioned set of type bars for operating said conditioning means thereby conditioning the other set of type bars and for actuating said hammer.

3. In a typewriter having a frame and a carriage mounted for movement on said frame relative to a printing station, a type bar supporting segment mounted on said frame at right angles with respect to movement of said carriage, two identical sets of type bars mounted respectively on opposite sides of said segment, said type bars having flexible extremities, type secured on the side of said extremities facing a printing plane defined by said carriage when said type bars are positioned at said printing station, means for flexing extremities of positioned type bars toward said printing plane to effect typing, means operative to condition one or the other of said sets of type bars for operation, means for selectively positioning a type bar in a conditioned set of type bars at said printing station, and control means responsive to the movement of said selected type bar toward said printing station for operating said conditioning means whereby the other set of type bars is conditioned for operation, and means responsive to said control means for operating said type bar flexing means.

4. In a typewriter as recited in claim 3 further comprising carriage escapement means responsive to said control means for effecting movement of said carriage.

5. In a typewriter as recited in claim 3 further comprising means associated with each type bar for maintaining a selectively positioned type bar stationary at said printing station over a predetermined interval.

6. In a typewriter having a frame and a carriage mounted for movement on said frame relative to a printing station, a type bar segment mounted on said frame at right angles to the direction of carriage movement, two identical sets of type bars mounted respectively on opposite sides of said segment, said type bars being positionable at said printing station in a plane parallel to the printing plane of said carriage, said type bars having flexible extremities, type secured on the side of said extremities facing said printing plane, means for flexing said extremities toward said printing plane to effect printing, type bar selecting means, power means for driving a selected one of the type bars in one of said sets of type bars into printing position at said printing station, control means responsive to the movement of said selected type bar toward said printing station, and means responsive to said selecting means and to said control means for selecting a type bar for operation from said other set of type bars.

7. Apparatus as recited in claim 6 wherein said control means comprises photoelectric means, and means responsive to said photoelectric means for alternately conditioning said sets of type bars for operation by said type bar selecting means.

8. In a typewriter having a frame, a carriage mounted for movement on said frame, a platen rotatably supported by said carriage and tangent to a vertical plane in which a printing line lies, a type bar segment centrally mounted on said frame in front of and at right angles to the axis of said platen, back to back type guides mounted on said segment and defining a printing station parallel to said printing plane, two identical sets of type bars mounted respectively on opposite sides of said segment, means for actuating selected type bars alternately from said two sets of type bars including means for maintaining said type bar stationary at said printing station over a predetermined interval, and hammer means operable to strike type bars at said printing station to effect printing.

9. In a typewriter having a frame, a platen supported for movement relative to said frame and defining a printing line lying in a vertical plane tangent thereto, a type bar supporting segment supported on said frame in a plane perpendicular to said vertical plane, a set of type bars pivotally mounted on each side of said segment, said type bars being adapted for movement to a printing station forward of and parallel to said vertical plane, bistable means for conditioning one or the other of said type bar sets for operation, means for selectively driving a type bar in a conditioned set to said printing station, sensing means responsive to the movement of a type bar from a conditioned type bar set to said printing, a hammer, and control means operative in response to said sensing means for operating said hammer to drive a positioned type bar toward said printing line to effect printing and for switching said bistable means.

References Cited in the file of this patent UNITED STATES PATENTS 1,608,837 Bryce Nov. 30, 1926 

